U.S. patent number 11,177,139 [Application Number 16/480,304] was granted by the patent office on 2021-11-16 for electronic card with printed circuit comprising an antenna with integrated slots and method for the production thereof.
This patent grant is currently assigned to INSTITUT VEDECOM. The grantee listed for this patent is INSTITUT VEDECOM. Invention is credited to Friedbald Kiel.
United States Patent |
11,177,139 |
Kiel |
November 16, 2021 |
Electronic card with printed circuit comprising an antenna with
integrated slots and method for the production thereof
Abstract
The electronic card with printed circuit (1) comprises at least
one antenna with slots (AT) including a cavity (15) and a metal
conductive layer (17) covering the cavity and having a plurality of
slots (S17). The slots form openings in the metal conductive layer.
In accordance with the invention, the cavity is formed, by removal
of material, in the thickness of the printed circuit. The cavity
also comprises a metallisation layer (16) on the walls and the
metal conductive layer is formed in a plate attached on the
electronic card with printed circuit and closes the cavity.
Inventors: |
Kiel; Friedbald (Fontainebleau,
FR) |
Applicant: |
Name |
City |
State |
Country |
Type |
INSTITUT VEDECOM |
Versailles |
N/A |
FR |
|
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Assignee: |
INSTITUT VEDECOM (Versailles,
FR)
|
Family
ID: |
1000005934906 |
Appl.
No.: |
16/480,304 |
Filed: |
January 29, 2018 |
PCT
Filed: |
January 29, 2018 |
PCT No.: |
PCT/FR2018/050195 |
371(c)(1),(2),(4) Date: |
July 23, 2019 |
PCT
Pub. No.: |
WO2018/142051 |
PCT
Pub. Date: |
August 09, 2018 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
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US 20190371622 A1 |
Dec 5, 2019 |
|
Foreign Application Priority Data
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01Q
21/064 (20130101); H01Q 13/18 (20130101); H01L
21/4857 (20130101); H05K 1/145 (20130101); H05K
3/4697 (20130101); H05K 2203/063 (20130101); H05K
2201/10098 (20130101) |
Current International
Class: |
H01L
21/48 (20060101); H01Q 13/18 (20060101); H01Q
21/06 (20060101); H05K 1/14 (20060101); H05K
3/46 (20060101) |
Field of
Search: |
;438/107 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
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2564466 |
|
Apr 2014 |
|
EP |
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2901062 |
|
Nov 2007 |
|
FR |
|
2011030277 |
|
Mar 2011 |
|
WO |
|
Other References
International Search Report for PCT/FR2018/050195 dated May 8,
2018. cited by applicant .
Written Opinion for PCT/FR2018/050195 dated May 8, 2018. cited by
applicant.
|
Primary Examiner: Ullah; Elias
Attorney, Agent or Firm: Sandberg Phoenix & von Gontard,
P.C.
Claims
The invention claimed is:
1. An electronic printed circuit board comprising at least one
slotted antenna, said slotted antenna comprising: a cavity defined
in said electronic circuit board, said cavity comprising a wall and
a floor, at least said wall having a metallization layer thereon;
and a conductive metal layer covering said cavity, said conductive
metal layer having opposed major surfaces and multiple slots formed
in one of said major surfaces defining openings in said conductive
metal layer, wherein said cavity is formed, through the removal of
material, in the thickness direction of said electronic printed
circuit board, and wherein said conductive metal layer, featuring
said multiple slots, is formed in defined by a wafer and is added
to said electronic printed circuit board such that said conductive
metal layer closes said cavity.
2. The electronic printed circuit board according to claim 1,
wherein said conductive metal layer, featuring said multiple slots,
is supported by a dielectric layer closing said cavity, with said
conductive metal layer being positioned outside said cavity.
3. The electronic printed circuit board according to claim 2
wherein said conductive metal layer, featuring said multiple slots,
and said dielectric layer are formed in a CCL-type laminate wafer
or an RCC-type wafer.
4. The electronic printed circuit board according to claim 1,
wherein said conductive metal layer, featuring said multiple slots,
is supported by a dielectric layer closing said cavity, with said
conductive metal layer being positioned inside said cavity.
5. The electronic printed circuit board according to claim 4
wherein said conductive metal layer, featuring said multiple slots,
and said dielectric layer are formed in a CCL-type laminate wafer
or an RCC-type wafer.
6. The electronic printed circuit board according to claim 1,
wherein said metallization layer is made of copper.
7. The electronic printed circuit board according to claim 1,
wherein said electronic printed circuit board comprises a plurality
of said slotted antennas, with said slotted antennas being combined
within a network of antennas.
8. The electronic printed circuit board according to claim 1,
wherein said electronic circuit board is of the multilayer
type.
9. The electronic printed circuit board according to claim 1,
wherein said electronic circuit board includes a radio transmitter
comprising at least one said slotted antenna and an electronic
component positioned at a bottom of said cavity of the slotted
antenna.
10. The electronic printed circuit board according to claim 9,
wherein said electronic circuit board comprises a conductor in
contact with said electronic component, said conductor being
operable to extract heat produced by said electronic component.
11. The electronic printed circuit board according to claim 1,
wherein said electronic circuit board includes a radio receiver
comprising at least one said slotted antenna and an electronic
component positioned at a bottom of said cavity of the slotted
antenna.
12. A method for the production of an electronic printed circuit
board, said electronic printed circuit board comprising at least
one slotted antenna, said slotted antenna comprising a cavity
formed in said electronic printed circuit board and a conductive
metal layer covering said cavity, said conductive metal layer
having opposed major surfaces and multiple slots formed in one of
said major surfaces defining openings in said conductive metal
layer, said method including photolithography and engraving steps,
said method further including: a step of removing material from
said electronic circuit board is removed to form a said cavity in
the thickness direction of the electronic printed circuit board, a
metallization step in which to form a metallization layer is formed
on the walls of the said cavity, and a step in which a wafer
including said conductive metal layer is applied to said electronic
printed circuit board to close said cavity.
13. The method according to claim 12, wherein said method also
includes a step in which a plurality of printed circuit wafers are
laminated to form said electronic printed circuit board.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the US National Stage under 35 USC .sctn. 371
of International Application No. PCT/FR2018/050195, filed 29 Jan.
2018 which claims priority to French application 1750851 filed on 1
Feb. 2017, the content (text, drawings and claims) of both said
applications being incorporated herein by reference.
BACKGROUND
The invention concerns the general field of wireless
communications. More specifically, the invention relates to an
electronic printed circuit board, comprising at least one
integrated slotted antenna. The invention also relates to a method
for the production of an electronic printed circuit board
comprising this slotted antenna.
Wireless communications via microwave radio-relay systems have
developed spectacularly over the past twenty years or so. As a
result of the convergence between the internet, IT, audiovisual
technology, cell-phone networks, and the availability of
high-performance mobile communication terminals, new communication
methods have emerged. Various types of well-known wireless
communication technologies have been developed: for example,
technology specified by the Bluetooth.RTM. standards for personal
wireless networks, WiFi.RTM. for local wireless networks, and
UMTS.RTM. and LTE.RTM. for wireless cell-phone networks.
Even more significant growth is foreseen with the development of
connected objects and the emergence of so-called "ambient
computing," whereby people and objects in the same environment can
communicate via wireless networks. Objects are fitted with "chips"
and means of wireless communication, enabling them to adapt and
interact with their environment and with people.
On-board wireless networks in the various air, road, rail and sea
transportation means are also set to experience rapid growth.
Deploying a large number of sensors via a wireless network also has
many applications: for example, in the fields of instrumentation,
the environment, home automation, healthcare, process monitoring
and safety.
Radio antennas are key components for wireless communication
devices and represent a significant obstacle to the miniaturization
of radio communication modules and cost reduction. The
miniaturization of radio antennas and their reduced cost are
desirable to facilitate the integration of wireless communication
modules into systems, and in particular, those of the SiP (System
in Package) type.
Slotted microantennas in ultrahigh and microwave frequency bands
are used for cellular telephony. The inventor is thus aware of a
slotted antenna inserted into a printed circuit board and which is
typically fitted to cell phones in the frequency band spanning from
800 MHz to 1 GHz. However, this antenna offers limited radio
performance, particularly in terms of gain.
Slotted antennas of the waveguide type or with a cavity offer
improved performance. Such antennas are, for example, described in
the U.S. Pat. No. 6,049,311A, EP App. No. 2564466A1, and US Pub.
No. 2004/004576A1. However, with regard to these state of the art
antennas, the addition of a waveguide or a cavity increases the
antenna's overall dimension and has a significant impact on its
cost.
The expected major growth in the wireless communication network
market requires technological progress for slotted antennas that
offer good performance and can be inserted into electronic printed
circuit boards, with reduced overall dimensions and costs, to
produce an SiP-type (System in Package).
SUMMARY
According to a first aspect, an electronic printed circuit board is
disclosed which comprises at least one slotted antenna, with the
slotted antenna comprising a cavity and a conductive metal layer
covering the cavity and featuring multiple slots, with the slots
forming openings in the conductive metal layer.
In accordance with an aspect of the printed circuit board, the
cavity is formed through the removal of material in the thickness
direction of the electronic printed circuit board and includes a
metallization layer on the walls of the cavity, and the conductive
metal layer, featuring multiple slots, is formed in a wafer
transferred onto the electronic printed circuit board and closes
the cavity.
According to a specific characteristic, the conductive metal layer
with multiple slots is supported on a dielectric layer closing the
cavity, the conductive metal layer being positioned outside the
cavity.
According to a specific characteristic, the conductive metal layer
with multiple slots is supported on a dielectric layer closing the
cavity, the conductive metal layer being positioned inside the
cavity.
According to another specific characteristic, the conductive metal
layer with multiple slots and the dielectric layer are formed in a
CCL-type laminate wafer or an RCC-type wafer.
According to another specific characteristic, the metallization
layer is made of copper.
Depending on the specific embodiment, the electronic printed
circuit board comprises a number of slotted antennas, with the
slotted antennas being combined within a network of antennas.
According to another specific characteristic, the electronic
printed circuit board is of the multilayer type.
According to another specific embodiment, the electronic printed
circuit board includes a radio transmitter comprising at least one
slotted antenna and an electronic component positioned at the
bottom of the cavity of the slotted antenna.
According to another specific characteristic, the electronic
printed circuit board comprises a conductor in contact with the
electronic component, whose function is to extract heat generated
by the electronic component.
According to another specific embodiment, the electronic printed
circuit board includes a radio transmitter comprising at least one
slotted antenna and an electronic component positioned at the
bottom of the cavity of the slotted antenna.
According to another aspect, a production method for an electronic
printed circuit board is also disclosed, wherein the electronic
printed circuit board comprises at least one slotted antenna, with
the slotted antenna comprising a cavity and a conductive metal
layer featuring multiple slots. The slots form openings in the
conductive metal layer, with the production method including
photolithographic and etching steps. In accordance with an aspect
of the method, the production method includes a step to remove
material in order to form the cavity in the the thickness direction
of the electronic printed circuit board, a metallization step to
form a metallization layer on the cavity walls, and a step to
transfer a wafer including a conductive metal layer onto the
electronic printed circuit board so as to close the cavity.
According to a specific characteristic, the production method also
comprises a step to laminate a number of printed circuit wafers to
form the printed circuit board.
DESCRIPTION OF THE FIGURES
Other advantages and characteristics of this invention will become
more apparent by reading the detailed description below of various
specific embodiments of the invention, with reference to the
appended drawings, in which:
FIG. 1 is a partial sectional view of an electronic printed circuit
board in a state before a slotted antenna is inserted to produce an
electronic board;
FIG. 2A is a partial sectional view of the electronic printed
circuit board shown in FIG. 1, in which a cavity of the slotted
antenna has been formed;
FIG. 2B is a partial sectional view of a number of printed circuit
wafers before they are laminated to form the electronic printed
circuit board featuring the cavity of the slotted antenna;
FIG. 3 is a partial sectional view of the electronic printed
circuit board shown in FIG. 1, in which the slotted antenna has
been integrated;
FIGS. 4A and 4B are top and side views of a first example of a
slotted wafer included in the antenna;
FIGS. 5A and 5B are top and side views of a second example of a
slotted wafer included in the antenna; and
FIGS. 6A and 6B are top and side views of a third example of a
slotted wafer included in the antenna.
DETAILED DESCRIPTION
With reference to FIGS. 1, 2A, 2B and 3, the steps to produce a
specific embodiment of a slotted antenna in an electronic printed
circuit board are described.
FIG. 1 shows a multilayer-type electronic printed circuit board 1
into which the slotted antenna must be inserted.
As shown in FIG. 1, the standard form of the electronic printed
circuit board 1 comprises multiple conductive copper layers 10 and
dielectric layers 11. Conductive connection patterns are formed in
the conductive layers 10 and in through holes 12 to interconnect
the conductive patterns located in the various layers. The active
and passive electronic circuit components, such as the electronic
component 13, are buried between the inner layers of the board 1
during its production.
Well-mastered production techniques for printed circuit boards are
generally used to produce the multilayer electronic printed circuit
board 1. Thus, the production method may use copper-clad laminates
(CCL), which may or may not be filled with fiberglass; dielectrics
preimpregnated with epoxy-type resin (called prepeg); thin copper
sheets or wafers, possibly coated with resin, of the RCC-type
(Resin-Coated Copper); and adhesives. The production method may use
a combination of techniques, including lamination,
photolithography, wet etching, electroplating, mechanical and/or
laser milling and drilling, and other techniques.
The ZA area, shown in FIG. 1, is the area of the board 1 into which
the slotted antenna must be inserted. An electronic component 13 is
inserted into this area ZA, which in this embodiment is an RF
transistor for transmitting electromagnetic waves. The goal here is
to produce a radio transmitter by combining a slotted antenna with
the transistor 13. Of course, a radio receiver in the board 1 will
be produced in a similar way.
As shown in FIG. 1, the transistor 13 is buried between the inner
layers 10, 11 of the board 1. The transistor 13 includes
electrodes, not visible in FIG. 1, which are welded to a copper
connection pattern in the board 1.
A conductor C10, comprised of a thick copper layer, is provided to
cool down the transistor 13. The function of this conductor C10 is
to extract heat generated by the transistor 13 into a heat sink
(not shown). Through holes 12 are created here to link a metal
surface of the transistor 13 to the conductor C10. The conductor
C10 may or may not be required, depending on the power of the radio
transmitter. When the conductor C10 is required, its dimensions
will vary according to the heat load to be evacuated. The conductor
C10 is less likely to be required in the case of a radio
receiver.
An antenna cavity 15, shown in FIG. 2A, is integrated in the
thickness direction of the board 1. In this embodiment, an indexing
pattern, shown as 14 in FIG. 1, has been formed on the top face of
the board 1 so as to allow indexing of the material-removing tool
used to hollow out the cavity 15.
As shown in FIG. 2A, material is removed above the transistor 13 to
extract the desired volume for the cavity 15. This material is
typically removed using a milling cutter, laser and/or
photochemical etching techniques enabling the metal layers to be
cut accurately.
The dimensions of the cavity 15 are typically determined according
to the carrier wavelength.
The walls of the cavity 15 are then coated with a metallization
layer 16, typically copper, so as to form a waveguide. The
metallization layer 16 is formed here by electroplating.
According to another embodiment shown in FIG. 2B, an electronic
printed circuit board 1' with integrated antenna cavity 15' is
formed by laminating a number of printed circuit wafers. The
embodiment in FIG. 2B has three printed circuit wafers, i.e. P1, P2
and P3.
Each of the wafers P1, P2 and P3 is formed using production
techniques for multilayer printed circuit boards.
Removal of material M1, M2 is carried out here in wafers P2, P3 so
as to remove a total volume corresponding to the desired volume for
the cavity 15'. This removal of material M1, M2 is carried out in a
similar way to the removal of material for the cavity 15, i.e.
using a milling cutter, laser and/or photochemical etching
techniques.
The wafers P1, P2 and P3 are then laminated by pressing and passing
through a vacuum laminating oven, after their lamination surfaces
have been coated, for example, with an epoxy-type polymerizable
resin to ensure their bonding. Produced in this manner is the
multilayer electronic printed circuit board 1' with the cavity 15'.
As in the case of the cavity 15' of the board 1, a metallization
layer (typically made of copper) is applied to the walls of the
cavity 15' so as to form a waveguide. At this production stage, the
board 1' is in the same state as the board 1 shown in FIG. 2A.
The description below continues by considering the electronic
printed circuit board 1 at the production stage shown in FIG.
2A.
The installation of a wafer 17, designed to close the upper part of
the cavity 15, completes the production of the antenna. The wafer
17 is typically a printed circuit wafer in which multiple slots S17
are formed, and which can be seen in FIG. 2A. The slots S17 form
openings in the metal layer of the electronic printed circuit
board.
A flange 18 is provided at the top of the walls of the cavity 15.
The flange 18 guarantees the exact position of the wafer 17 in the
opening of the cavity 15. It must be positioned exactly in order to
respect the defined dimensions of the antenna. The wafer 17 is
secured by means of bonding in the opening of the cavity 15.
The antenna AT is shown in its completed state in FIG. 3. As shown
by FIG. 3, the antenna AT is fully integrated into the electronic
printed circuit board 1.
Various embodiments of the slotted wafer are shown in FIGS. 4A, 4B,
5A, 5B and 6A, 6B.
FIGS. 4A, 4B, and 5A, 5B respectively show the first and second
embodiments 17a and 17b of the slotted wafer. The slotted wafers
17a and 17b are equivalent, except for the fact that wafer 17a
closes the cavity 15 of the antenna AT with its copper surface CF
positioned outside the cavity 15, whereas wafer 17b closes the
cavity 15 of the antenna AT with its copper surface CF positioned
inside the cavity 15.
The slotted wafer 17a, 17b is produced, for example, from a thin
laminate wafer (CCL) or an RCC wafer with a dielectric layer DF and
a copper layer CF.
The slot patterning shown in FIG. 4A is achieved using standard
photolithographic and engraving techniques. The slots S17 are
produced by removing copper. The slots S17 maintain the dielectric
layer.
FIGS. 6A, 6B show a third embodiment 17c of the slotted wafer.
The slotted wafer 17c here is produced from a thin wafer of copper.
The slot patterning is achieved, for example, through photochemical
etching.
Of course, in some applications, several antennas in accordance
with the invention may be combined within a network and produced on
the same electronic printed circuit board. It would therefore be
possible to produce the desired lobe forms.
The invention is not restricted to the specific embodiments
described here by way of examples. A person skilled in the art, in
accordance with the invention's application, may apply various
modifications and alternatives within the scope of the appended
claims.
* * * * *